Discussion
Raphanus savitus is a cool-season crop. The radish seeds are living organisms that lie in the state of dormancy and affected by different factors such as air, temperature, light and moisture. Every single seed of radish can grow into a seedling provided it gets an ideal environment. However, that doesn’t happen normally. The experiment examines the effect of acid, base, caffeine, and microwaves on the germination of Raphanus savitus seeds.
The main purpose of the experiment was to test the negative and positive effects of different environmental factors on seed germination. The data was collected after two weeks. It was hypothesized that certain chemicals and temperatures will have an effect on normal radish cell germination. As the experiment was initiated, certain hypotheses were formulated concerning the possible effects of pH, microwave, caffeine, and soil chemistry on germination rates in plants. The results and their analyses tested those hypotheses and found them to be either true or untrue.
The results of the experiment show that all the above factors such as acid, base, caffeine, fertilizer and microwaves did have an effect on the seed germination whether positive or negative. The observations show different growth in the length of the roots under different environmental factors. The data collected shows a clear difference in the rates of the germination as well as growth of the Radish seeds. The microwave treatment was the only factor that had a positive effect on the seed germination, while caffeine, fertilizer and pH showed a negative effect on the growth of the seed.
This pH experiment shows that how germinating Raphanus savitus can be affected by the presence of a weak acid and a strong acid, or a weak base and a strong base. The highest germination is seen in pH 7 or with neutral water suggesting that neutral pH is best suited for seed germination. In conditions where rain is acidic or basic, it is likely that seed germination will be negatively affected. When Raphanus sativus seeds were kept in pH 7, they showed substantial increase in mean root length. The higher alkalinity and acidity can destroy function of proteins and the membrane required for osmosis (Stubbendieck). Thus, the right H+ ion concentration is essential to be maintained within a range in cells that are made of proteins.
The presence of caffeine was a negative factor for seed germination. Unlike previous studies (Ransom), our study did not even show a small positive effect even when the caffeine content in the solution was small. The species we studied may have specific characteristics that make caffeine a negative factor for seed germination as opposed to the experiments previously described in the literature.
According to Bokorny 1911, caffeine has effect on striped muscle and plant cells. Delayed germination is seen in seeds treated with caffeine. Thu, one can assess the damaging effect of caffeine on plants and seeds and seeds based on earlier studies when seeds given caffeine treatment did not show normal germination. Caffeine increases protease activity and concentrated solutions of caffeine can discourage germination. The present study is in conformation with the previous study and these tests indicate a negative effect of caffeine on radish seed germination in the experiment.
The different microwave periods too effect on germination seeds and were in fact the only positive variable. Different microwave methods of conditioning have been used in recent years on different seeds (Ragha). It can be concluded that electric fields of different types can stimulate the seeds and promote plant growth. The hypothesis that exposure of seeds to microwave increases the germination was proved correct.
Raphanus sativus seeds were treated to different concentrations of fertilizer and the results show that significant growth in root length is seen in those seeds not treated with fertilizer. Those that were given fertilizer treatment showed poor growth. Maxton, 1927 has reported a decline in growth with increased salt concentration. The reason behind is osmotic inhibition where the plant growth is prevented due to excess of solutes. Different plants show varied growth with in different salinities. When fertilizers were given to radish seeds, the germination was reduced.
When viability is less, there is damage to seed. Seed vigor is a measurement of the quantity of damage. If the seed does not have vigor stressors will not let seedling grow, stressors being cold or warm weather, high humidity. But if the seed has vigor it will grow in spite of the stressors as if it was on stimulants.
However, as was expected, there were several variables that could not be fully controlled during our experiment. The variable of temperature may not have been constant throughout the entire experiment. A conscious effort was made to keep all variables except temperature constant. Thus, there were certain possible sources of errors in this experiment as the experiment required high maintenance. It needed regular checking and readjusting of everything, for example positions, lights, water and the settings. The issues of evaporation need to be dealt with daily so as to maintain continuity.
The hypothesis is correct as far as saying that environmental factors do have an impact on seed germination. However, further investigations and scientific experiments need to be done keeping the variables involved under better control. This will expand our knowledge of the effect of different environmental factors on the germination of radish seed. One has to decide how many radish seeds and how much liquid should be used. An important factor to consider in this experiment is to realize that 100% germination is not guaranteed and one can expect some variability in response. There must be sufficient liquid to hydrate the seeds as well as diffusion of gasses that should be maintained.
The experiment shows that seed germination is influenced by several environmental factors (Bewley). Whether it is the presence of weak or strong acid or base, different concentrations of caffeine and microwaves, or the effect of fertilizer, there is a significant effect seen in the germination of the radish seeds. Weak acids have a stimulating effect on seeds as they weaken the seed coat and help the seed to germinate faster and easier. However, strong acids and strong bases have a negative impact on the seed germination. This data does show a clear and mathematically supported illustration to compare the effects on germination.
One can repeat the experiment for different types of plants seeds, different soil types and for a wider range of temperatures. One should think about other seeds and study if the size of the seed makes any difference or how deep the seed is planted. Apart from the length of the root, its mass and girth too need to be measured. The experiment offers an opportunity to learn about the rate of germination of a seed and growth rate of a plant. The beneficial and harmful effects of environment factors like fertilizers, pH treatment, different concentration of caffeine and microwave treatment help understand the importance of environmental factors on germination of seeds.
Literature Cited:
Maxton, Jacob l. "Effect of Fertilizers on the Germination of Seeds." Soil Science 23.5 (1927): 335-42. Print.
Stubbendieck, J. 1974. Effect of pH on germination of three grass species. Journal of Range Management Archives 27.1: 78-79.
Ransom, F. 1912. The effects of caffeine upon the germination and growth of seeds. Biochemical Journal 6:151.
Ragha, Lakshmappa. 2011. Effects of low-power microwave fields on seed germination and growth rate Journal of electromagnetic analysis and applications. 3:165.
Shimomura, S. "The Effects of Ultrasonic Irradiation on Sprouting Radish Seed".1990. 1665-1667 vol.3. Print.
Bewley, J. Derek, et al. Seeds: Physiology of Development, Germination and Dormancy. New York, NY: Springer, 2013. Print.
